Professor Johnathan Napier, a pioneer in plant biology based at Rothamsted Research, and
leading fish nutritionist Professor Douglas Tocher from University of Stirling have been
collaborating for nearly 20 years on finding a sustainable solution to deliver novel sources
of Omega-3 fatty acids.
The oceans are under relentless pressure as the world population grows and we increasingly
look to fish as an important food supply. Alongside this is our increasing reliance
on fish to provide us with Omega-3, a polyunsaturated fatty acid that our bodies need to function.
It has led to the quest to find a sustainable source of fish oils and the unlikely solution
could come from a plant called Camelina.
Professor Napier has carried out field trials in the UK to create the plants. The crops
have been genetically modified enabling them to produce these particular Omega-3 fatty
acids in their seed oil, something no other plant can do. Together they are embarking
on a new aqua feed trial delivering an alternative fish feed solution using a genetically modified
oil ingredient to Atlantic farmed salmon which they hope will relieve the pressure on stressed
marine resources.
So we've been interested in trying to work out how could we make a new land-based source
of fish oil so we can basically secure the supply of these really important nutrients
in a way that's not going to be taking them out of the ocean, but making them on land
using agriculture to produce them. And so we spent probably a decade trying to develop
plants to do that and we were successful through support from BBSRC and now we're in a position
to actually test those land-based supply of fish oils in in aquaculture.
Omega-3 fish oils, also known as Omega-3 long-chain polyunsaturated fatty acids, such as EPA and
DHA, have been proven as beneficial to human health reducing the risk of cardiovascular
disease and other metabolic diseases. These oils are credited as being crucial for human
nutrition but the wild fish stocks which provide them are at maximum levels of managed sustainability
meaning the current fish stocks are simply not able to provide enough nutrition for a
growing global population.
For the fish to have them in their flesh they have to be fed them and so we've been using
fish meal and fish oil. But they are also at their sustainable limit so in the last
10 years, to in a drive to make fish feeds and salmon feeds more sustainable, we've been
increasingly replacing fish meal and fish oil with terrestrially derived products like
plant meals and vegetable oils. And unfortunately they don't contain any long-chain Omega-3
polyunsaturated fatty acids and so because they don't contain any the levels in the fish
are also declining. So over the last 10 years the levels have declined by about 1/2 so that
when you have a portion of salmon today it's maybe got about half the level of EPA and
DHA, these long-chain Omega-3, that they used to have 10 years ago.
Walking around the trial site it's clear Professor Napier is enthusiastic about the latest stage
in this ongoing research using the Camelina plant.
For me it's also the culmination of a lot of research to get us to the point here where
we are going to test our plant derived Omega-3 fish oils in a salmon farm to see how they
perform. And we're going to do this for at least a year to feed their diets to the fish.
So it's really exciting.
The young fish have already been added to the pens in which they'll be fed and monitored
during the course of the trial. The pens were outside in seawater and are being fed and
monitored by a team of experts. Nearby there are salmon that will be fed normal fish feed
so that the two can be compared. The team looking after the fish ensure they're fed
regularly throughout the day and the amount of food not being consumed is monitored using
underwater cameras.
Simply by looking at their behaviour and their activity, their feeding behaviour, feed into
anything that comes shows up there will be able to be monitored on a daily basis. At
regular intervals the fish are weighed and so the fish get inspected more closely at
that time. And also we will be taking samples at intervals in which we will be able to determine
physiologically and biochemically that these feeds are having no negative impacts on the
fish health.
During the course of the trial Dr Monica Betancor, a research fellow at University of Stirling,
plays a crucial role by checking on the salmon's health and collecting data.
What I do when I come here it's simple, take the different samples that we need for the
analysis. In this case we assign both the performance of the fish so it will be from
simple biometry so measuring the fish, weigh-in, then just to see how the growth is if there
was any difference between the fish fed the commercial diet and fish fed the diet with
the new Camelina and also getting different type of samples that will help to see how
the fish are accumulating Omega-3 in their different tissues. Also to see the impact
that the diet can have from a molecular point of view and also to assess the health of the
fish.
The success of this trial is fuelled by the determination of both Professors to return
to levels of Omega-3 fatty oils in farm fish to those of a decade ago.
And we expect that the fish at the end of this trial will have pretty much the same
levels of EPA and DHA that farmed salmon had about 10 years ago, which is a tremendous
benefit to the consumers.
Professor Napier is keen to stress that the results of the trial should complement and
not replace existing aquaculture activities. If successful the project could provide a
potential solution to the sustainability issue in supplying fish oils to farmed fish.
This is a really significant activity for us because it'll demonstrate that we can use
our Omega-3 fish oils from plants across the whole life cycle of the salmon production
season. And so once we know that that really gives us the demonstration, the proof, that
this really is a basically a solution to this sustainability issue that relates to the supply
of fish shores. And so for us then the next activity would be to think about 'okay how
can we move this into actual commercialisation?', 'How can we commercialise this technology
so that we deliver impact?'
The farmed salmon here in Scotland could help provide the solution to relieving pressure
on the world's stressed marine resources.